1. Field of the Invention
The invention relates to an electronic circuit arrangement.
2. Description of Related Art
For conventional chip production strategies, it is normal, as described by way of example in U.S. Pat. No. 6,368,902 B1, to provide redundant components in integrated memories, in order to improve the yield of serviceable chips from the production process. The yield of integrated memories is increased significantly by the replacement of faulty cells by means of an additional circuit, which is provided as a redundant circuit on a respective chip. The additional circuits normally have contact made with them, and are thus activated or not activated, selectively, by means of electrically conductive links (referred to in the following text as electrical fuse links), by increasing the electrical resistance of a respective electrical fuse link, or by “burning through” the respective electrical fuse link. The yield of serviceable chips is increased by selective variation of the electrical resistance of the respective electrical fuse link within an integrated circuit, thus resulting in lower production costs for the production of the chips.
The electrical fuse link is taken into account in the design of the respective integrated circuit. The electrical fuse link is deliberately “burnt through”, for example by means of an electric current flowing through the electrical fuse link, with the electrical current level being sufficient to open the electrical fuse link. Alternatively, a current which is weaker than that which is required to completely disconnect the electrical fuse link can be applied to the electrical fuse link, with the consequence that the electrical fuse link only partially degenerates, and the electrical resistance of the electrical fuse link is increased. This process of deliberate burning-through or degeneration of the electrical fuse link is also referred to as programming of the electrical fuse link.
In the electronic circuit arrangement, the electrical fuse link is preceded by an electronic component, and is supplied with current by means of a field-effect transistor in order to degenerate or finally cut through the electrical fuse link. The field-effect transistor is a transistor in which a control voltage which is applied to a high-impedance control electrode (gate) produces an electrical field in a current-carrying channel. This field effect influences the conductivity of the channel, whose connections are referred to as the source and drain.
The document U.S. Pat. No. 6,162,686 A discloses a structure for a fuse link composed of metal, in which the fuse link is melted by means of a laser beam which is directed at the fuse link. Tungsten is used as the fusible material.
The document EP 1 304 741 A1 discloses a fuse element with a polysilicon layer and contacts which are fitted to it at right angles. Metal lines are coupled to the contacts. Overlap areas of the contacts with the respective metal lines are designed such that electric current which flows through the metal lines melts the contact area between the contact and the respective metal line.
The document EP 853 341 A2 discloses a fuse link, which is cut through by means of a laser at the end of a metal track.
The document U.S. Pat. No. 6,440,834 B2 discloses the use of organic material as the fusible material in a fuse link.
Furthermore, the documents DE 100 26 251 A1 and DE 198 52 429 Cl disclose drive circuits for programming a fuse.
The disadvantage of an electrical fuse link as described above is that the electrical fuse link will occupy a significant area that may be utilized for other circuitry. Accordingly, it is preferable to provide an electronic circuit arrangement having electrical fuse links which occupy less space.